JP2007127228A - Cylindrical bearing bush and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cylindrical bearing bush which keeps butted end faces in an intimate contact with each other and has an extremely high roundness on the inner peripheral surface without applying machining such as cutting and grinding onto the inner peripheral surface, and which is ideal for applications requiring a high dimensional precision, in particular, such as a motor bearing, a linear solenoid valve and a compressor, and also to provide its manufacturing method. <P>SOLUTION: In a cylindrical bearing bush 1, a multiple-layer material 4 consisting of a plate-like back metal 2 made of nonferrous metals and a lubrication-coated layer 3 made of a synthetic resin composition which is coated and formed integrally on the surface of the back metal 2 is cylindrically wound with the lubrication-coated layer 3 faced inward, keeps butted end faces 5 in an intimate contact with each other, and is formed with a roundness of the inner peripheral surface between 3 and 15 μm. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a cylindrical bearing bush having an extremely high roundness on an inner peripheral surface and a method for manufacturing the same.

Japanese Patent Publication No.53-36856 JP-A-5-99230 Japanese Patent Publication No. 61-11700

  A multi-layered material (see Patent Document 1) comprising a plate-shaped metal back metal and a synthetic resin sliding layer integrally formed on the surface of the back metal is formed into a cylindrical shape with the sliding layer inside. Cylindrical bearing bushes formed by rotation, so-called wound bushes, are widely used as support means for smoothly supporting shafts in various mechanical devices.

  Since this cylindrical bearing bush is formed by bending a multi-layered material into a cylindrical shape, a relatively large gap due to a spring back or the like, for example, a gap of about 1.5 mm is provided between the butt end faces of both ends of the cylindrical bearing bush. Occurrence is forced. When fixing the shaft support as a housing of the cylindrical bearing bush to the hole by press-fitting, due to the accumulation of the dimensional error (tolerance) of the hole of the shaft support and the thickness error of the cylindrical bearing bush, After the press-fitting, the inner diameter of the cylindrical bearing bush varies greatly, and it may be difficult to fix the cylindrical bearing bush in the hole with high inner diameter dimensional accuracy.

  In order to reduce the gap generated between the butt end faces of the both ends of the cylindrical bearing bush, there has been proposed a method of removing the residual stress of the synthetic resin layer generated at the time of molding by heat treatment and cooling treatment (see Patent Document 2). ). However, this method cannot eliminate the gap between the butted end faces of the cylindrical bearing bush, and it is difficult to fix the cylindrical bearing bush to the hole of the shaft support with high inner diameter dimensional accuracy.

  Further, as a method for improving the dimensional accuracy of the cylindrical bearing bush, the cylindrical bearing bush is press-fitted into the hole of the holder, a reference shaft core is fitted into the bearing bush, and the holder is compressed in the axial direction. Proposed a method to obtain the required dimensional accuracy of the inner diameter of the cylindrical bearing bush by giving the inner diameter of the cylindrical bush to the inner diameter of the shaft through the deformation of the bearing and adapting the inner peripheral surface of the bearing bush to the shaft core. (See Patent Document 3).

  Although this method is effective as a method for increasing the dimensional accuracy of the cylindrical bearing bush, the spring back of the plate-shaped backing metal cannot be eliminated from the multilayer material constituting the cylindrical bearing. After removal from the mold, a gap is formed between the end faces of the both ends of the cylindrical bearing bush, and the dimensional accuracy within the mold cannot be maintained as it is. This is particularly remarkable in a cylindrical bearing bush having a large curvature radius, for example, an inner diameter of 10 mm or more.

  The inventors pay attention to the back metal in the multilayer material, and as the material of the back metal, non-ferrous metal, specifically copper alloy made of oxygen-free copper and tough pitch copper, copper alloy made of phosphor bronze and brass, aluminum or aluminum It was confirmed that bending can be easily performed by using an alloy, and dimensional accuracy can be improved by upsetting.

  The present invention has been made on the basis of the above knowledge, and the purpose thereof is that the butt end faces are brought into close contact with each other, and the inner peripheral surface is extremely free from machining such as cutting and grinding. An object of the present invention is to provide a cylindrical bearing bush having a high roundness of an inner peripheral surface, and particularly suitable for an application requiring high dimensional accuracy such as a motor bearing, a linear solenoid valve, and a compressor.

  Another object of the present invention is to provide a method of manufacturing a cylindrical bearing bush in which the butted end surfaces are in close contact and the inner peripheral surface has a very high roundness without machining such as cutting and grinding. It is to provide.

  The cylindrical bearing bush of the present invention comprises a plate-like backing metal made of a non-ferrous metal and a sliding layer made of a synthetic resin composition formed integrally on the surface of the backing metal, with the sliding layer on the inside. The butt end faces are brought into close contact with each other and the roundness of the inner peripheral surface is 3 to 15 μm.

  According to the cylindrical bearing bush of the present invention, since the roundness of the inner peripheral surface is increased to 3 to 15 μm, it is not necessary to perform machining such as cutting and grinding on the inner peripheral surface.

  The first manufacturing method of the cylindrical bearing bush of the present invention is a multilayer material comprising a plate-like backing metal made of a non-ferrous metal and a sliding layer made of a synthetic resin composition integrally deposited on the surface of the backing metal. Are wound in a cylindrical shape with the sliding layer inside, and a substantially cylindrical bearing bush having a gap at the butt end face, a large diameter circular hole defined by the large diameter cylindrical inner wall surface and the large diameter circle A small-diameter cylindrical hole that is arranged adjacent to the hole in the axial direction and has a small-diameter circular hole smaller in diameter than the large-diameter circular hole, and that defines the large-diameter cylindrical inner wall surface and the small-diameter circular hole A step of preparing a mold having an annular surface interposed between the wall surface and extending radially inward from the large-diameter cylindrical inner wall surface and terminating at the small-diameter cylindrical inner wall surface; and a substantially cylindrical bearing A small-diameter cylindrical outer surface with a diameter that defines the final inner diameter of the bush and an axially adjacent to this small-diameter cylindrical outer surface And a large-diameter cylindrical outer surface having a larger diameter than the small-diameter cylindrical outer surface, and a small-diameter cylindrical outer surface between the small-diameter cylindrical outer surface and the large-diameter cylindrical outer surface. A step of preparing a mandrel comprising an annular surface extending radially outward and terminating at a large-diameter cylindrical outer surface; and fitting a substantially cylindrical bearing bush on the small-diameter cylindrical outer surface of the mandrel And a part of the small-diameter cylindrical outer surface of the cored bar fitted with a substantially cylindrical bearing bush on the small-diameter cylindrical outer surface to the small-diameter small-diameter hole of the mold, and the large-diameter cylindrical outer surface of the cored bar to the mold A step of upsetting the substantially cylindrical bearing bush by placing each of the large-diameter circular holes with a predetermined pressure on the core metal and applying the predetermined pressure to the remaining portion of the small-diameter cylindrical outer surface and the annular surfaces of the mold and the core metal; After processing, the cylindrical bearing bush whose butted end faces are in close contact with each other is taken out of the mold, and the roundness of the inner peripheral surface is 3 to 15 μm. and a cylindrical bearing bush formed with m.

  According to the first manufacturing method of the cylindrical bearing bush of the present invention, by performing upsetting on the substantially cylindrical bearing bush, the substantially cylindrical bearing bush has a small-diameter cylindrical outer surface whose outer peripheral surface is a core metal and a mold. The plastic flow follows the large-diameter cylindrical inner wall surface, and the butt end surfaces are brought into close contact with each other. As a result, the roundness of the inner peripheral surface of the cylindrical bearing bush after the cylindrical bearing bush is removed from the mold is increased to 3 to 15 μm.

  In the first manufacturing method of the cylindrical bearing bush of the present invention, the volume of the annular space formed by the large-diameter cylindrical inner wall surface and the remainder of the small-diameter cylindrical outer surface of the core metal and the respective annular surfaces of the mold and the core metal The upsetting process may be performed by reducing the volume until the volume is substantially close to the volume of the cylindrical bearing bush.

  The second manufacturing method of the cylindrical bearing bush of the present invention is a multilayer material comprising a plate-like backing metal made of a non-ferrous metal and a sliding layer made of a synthetic resin composition integrally formed on the surface of the backing metal. And a cylindrical shape having a diameter that defines a final outer diameter of the substantially cylindrical bearing bush, and a step of forming a substantially cylindrical bearing bush having a gap at the butt end surface. A mold body having a circular hole defined by the inner wall surface, a cylindrical end having a recess on one end side and surrounding an opening surface of the recess, and a cylindrical inner wall surface of the mold body A step of preparing a mold having a receiver having an outer surface, a small-diameter cylindrical outer surface having a diameter that defines a final inner diameter of the substantially cylindrical bearing bush, and fitted into a recess of the receiver. It is arranged adjacent to the small cylindrical outer surface in the axial direction and the A large-diameter cylindrical outer surface having a diameter larger than that of the cylindrical outer surface, and between the small-diameter cylindrical outer surface and the large-diameter cylindrical outer surface is radially outward from the small-diameter cylindrical outer surface. A step of preparing a mandrel having an annular surface extending and terminating at a large-diameter cylindrical outer surface; a step of fitting a substantially cylindrical bearing bush on the small-diameter cylindrical outer surface of the mandrel; and A part of the small-diameter cylindrical outer surface of the core metal, in which a substantially cylindrical bearing bush is fitted to the small-diameter cylindrical outer surface, is inserted into the circular hole from one open end of the circular hole of the mold main body. The cylindrical bearing is arranged in the recess of the receiving metal through the open end, and a predetermined pressure is applied to the receiving metal and the cored bar so that the remaining portion of the small-diameter cylindrical outer surface, the annular end surface of the receiving metal and the annular surface of the cored bar The process of upsetting the bush, and after the upsetting, take out the cylindrical bearing bush with the butted end surfaces in close contact with each other from the mold, Roundness is provided with a step of obtaining a cylindrical bearing bushes which are formed with 3 to 15 [mu] m.

  The second manufacturing method of the cylindrical bearing bush according to the present invention is such that a predetermined pressure is applied to the metal receiver and the metal core to form a substantially cylindrical bearing bush by the remaining portion of the small-diameter cylindrical outer surface, the annular end surface of the metal receiver and the annular surface of the metal core. Is subject to upset processing.

  According to the second method of manufacturing the cylindrical bearing bush of the present invention, the substantially cylindrical bearing bush is upset, so that the substantially cylindrical bearing bush includes a small-diameter cylindrical outer surface whose outer peripheral surface is a metal core and a die body. Plastic flow following the cylindrical inner wall surface, and the butted end surfaces are brought into close contact with each other. As a result, the roundness of the inner peripheral surface of the cylindrical bearing bush after the cylindrical bearing bush is removed from the mold is increased to 3 to 15 μm.

  In the second manufacturing method of the cylindrical bearing bush of the present invention, the volume of the annular space formed by the cylindrical inner wall surface, the remaining portion of the small-diameter cylindrical outer surface of the cored bar, the annular end surface of the receiver and the annular surface of the cored bar, It is preferable to perform the upsetting process by reducing the volume until it becomes close to the volume of the substantially cylindrical bearing bush.

  In the first and second manufacturing methods described above, the vicinity includes a case where the volume of the annular space is substantially equal to the volume of the substantially cylindrical bearing bush, but the substantially cylindrical bearing bush is substantially plastically flowed by the upset process. In other words, the degree to which cylindrical bearing bushes are densely arranged in the annular space.

In the first and second manufacturing methods of the cylindrical bearing bush of the present invention, the upset process is preferably 0.1 KN / mm ² to 2.0 KN / mm ² , more preferably 0.5 KN / mm ² to 1.2 KN. / Mm ² is applied.

  The third manufacturing method of the cylindrical bearing bush of the present invention is a multilayer material comprising a plate-like backing metal made of a non-ferrous metal and a sliding layer made of a synthetic resin composition integrally formed on the surface of the backing metal. And a cylindrical shape having a diameter that defines a final outer diameter of the substantially cylindrical bearing bush, and a step of forming a substantially cylindrical bearing bush having a gap at the butt end surface. A step of preparing a mold having a circular hole defined by the inner wall surface, a small-diameter cylindrical outer surface having a diameter that defines the final inner diameter of the substantially cylindrical bearing bush, and an axially adjacent to the small-diameter cylindrical outer surface. And a large-diameter cylindrical outer surface having a diameter larger than the diameter of the small-diameter cylindrical outer surface, and a diameter from the small-diameter cylindrical outer surface between the small-diameter cylindrical outer surface and the large-diameter cylindrical outer surface. Direction and extends outward and terminates in a large-diameter cylindrical outer surface Preparing a punch having an annular surface interposed therein, press fitting the substantially cylindrical bearing bush into a circular hole of the mold, and punching the substantially cylindrical bearing bush with the cylindrical inner wall surface of the mold. A sizing process in which the punch is pressed by an annular surface of the punch while being held between the outer surfaces of the small-diameter cylinder and moved inside the circular hole, and after the sizing process, a cylindrical bearing bush whose butted end surfaces are in close contact with each other is removed from the mold. And a step of obtaining a cylindrical bearing bush formed with a roundness of 3 to 15 μm on the inner peripheral surface.

  A fourth manufacturing method of the cylindrical bearing bush of the present invention is a multilayer material comprising a plate-like backing metal made of a non-ferrous metal and a sliding layer made of a synthetic resin composition integrally formed on the surface of the backing metal. Are wound in a cylindrical shape with the sliding layer inside, and a substantially cylindrical bearing bush having a gap at the butt end face, a large diameter circular hole defined by the large diameter cylindrical inner wall surface and the large diameter circle A tapered bore defined by a frustoconical surface that is continuous with the bore and gradually decreases in diameter in the axial direction, and is smaller in diameter than the large-diameter bore and has a substantially cylindrical bearing bushing. A step of preparing a mold having a small-diameter circular hole defined by a cylindrical inner wall surface having a diameter defining a final outer diameter dimension, and a diameter defining a final inner diameter dimension of a substantially cylindrical bearing bush. A small cylindrical outer surface and an axial direction to the small cylindrical outer surface And a large-diameter cylindrical outer surface having a diameter larger than the diameter of the small-diameter cylindrical outer surface, and a small diameter between the small-diameter cylindrical outer surface and the large-diameter cylindrical outer surface. Preparing a punch having an annular surface extending radially outward from the outer surface of the cylinder and terminating at the outer surface of the large-diameter cylindrical surface; and inserting the substantially cylindrical bearing bush into the large-diameter circular hole of the mold. While press-fitting and pressing the substantially cylindrical bearing bush between the large-diameter cylindrical inner wall surface of the mold and the small-diameter cylindrical outer surface of the punch and pressing the annular surface of the punch, the taper hole and the small diameter of the mold A sizing process for sequentially moving the inside of the circular hole, and after the sizing process, the cylindrical bearing bush whose butt end faces were in close contact with each other was taken out from the mold, and the roundness of the inner peripheral surface was formed to be 3 to 15 μm. Obtaining a cylindrical bearing bush.

  According to the third and fourth manufacturing methods of the cylindrical bearing bush of the present invention, by applying sizing to the substantially cylindrical bearing bush, the substantially cylindrical bearing bush has a small-diameter cylindrical outer surface and a die whose outer peripheral surface is a punch. As a result of plastic deformation following the cylindrical inner wall surface and the butted end surfaces being brought into close contact with each other, the roundness of the inner peripheral surface of the cylindrical bearing bush after removing the cylindrical bearing bush from the mold is 3 to 15 μm. Enhanced.

  Moreover, since the roundness of the inner peripheral surface of the cylindrical bearing bush obtained by the third and fourth manufacturing methods of the cylindrical bearing bush of the present invention is increased to 3 to 15 μm, the inner peripheral surface is cut, There is no need for machining such as grinding.

  In the fourth manufacturing method of the cylindrical bearing bush of the present invention, the inclination angle of the truncated conical surface with respect to the large-diameter cylindrical inner wall surface of the mold is preferably 0.5 to 5 °.

  In the present invention, the plate-like backing metal made of non-ferrous metal is oxygen free copper (C1020P, C1020R), tough pitch copper (C1100P, C1100R), phosphorous deoxidized copper (C1020P), which is standardized by JIS 3100 of Japanese Industrial Standard (JIS). C1201P, C1201R, C1220P, C1220R, C1221P, C1221R), Danshoku (C2100P, C2100R, C2200P, C2200R, C2300P, C2300R, C2400P, C2400R), Brass (C2600P, C2600R, C2680P, C2680P, C2680P, C2680P, C2680P, C2680P, C2680P, C2680P ), Free-cutting brass (C3560P, C3560R, C3561P, C3561R, 3710P, C3710R, 3713P, C3713R), white copper (C7060P, 7150P), phosphor bronze (C5111P, C5111R, C5102P, C5102R, C5191P, C5191R, C5212P, C5212R), white (C7351P, C7351R, C7451P, C7451R, C7521P, C7521P, C7521P, C7521P, 7541P, C7521P, C7521P, etc.) Copper and copper alloy plates and strips, and aluminum-manganese alloys such as A1085P, A1080P, A1070P, A1050P, A1100P, A1200P and other pure aluminum, A3003P, A3203P, A3004P, A3104P, A3005P, A3105P, etc. A5005P, A5052P, A5652P, A5154P, A5254P, A5454P, A 082P, A5182P, A5083P, aluminum, such as A5086P - magnesium alloy, aluminum, such as A6061P - magnesium - is selected and used from any of the plates, strips and the aluminum and aluminum alloys such as silicon-based alloy.

  The synthetic resin composition is mainly composed of a thermosetting synthetic resin selected from an epoxy resin, a polyimide resin and a polyamide-imide resin, and includes graphite, molybdenum disulfide, ethylene tetrafluoride resin, boron nitride and melamine cyanurate. It is preferred that it comprises at least one selected lubricating additive in a proportion of 2 to 60 vol%.

  According to the present invention, the butt end faces made of a multilayer material comprising a plate-like backing metal made of a non-ferrous metal and a sliding layer made of a synthetic resin composition integrally formed on the surface of the backing metal are closely packed with each other. Cylindrical bearing bush that is brought into contact with the inner peripheral surface without machining, such as cutting and grinding, and whose circularity of the inner peripheral surface is 3 to 15 μm and has high dimensional accuracy, and a method for manufacturing the same Can be provided.

  Next, the present invention and its embodiments will be described in more detail based on preferred embodiments shown in the drawings. In addition, this invention is not limited to these Examples at all.

  A cylindrical bearing bush 1 of the present invention shown in FIG. 1 includes a plate-like backing metal 2 made of a non-ferrous metal and a lubricating coating layer 3 as a sliding layer made of a synthetic resin composition formed integrally on the surface of the backing metal 2. 2 (see FIG. 2) is wound in a cylindrical shape with the lubricating coating layer 3 inside, and the butted end surfaces 5 are brought into close contact with each other, so that a perfect circle on the inner peripheral surface is formed. The degree is 3 to 15 μm.

  Next, the manufacturing method of the cylindrical bearing bush 1 mentioned above is demonstrated.

  A plate-like 0.8 mm thick plate made of oxygen-free copper (C1020R), tough pitch copper (C1100R), brass (C2600R), phosphor bronze (C5111R), aluminum (A1080P) and aluminum-magnesium alloy (A5052P) Back metal 2 was prepared, and the surface of these back metal 2 was subjected to a roughening treatment by shot blasting, and then the roughened surface was subjected to a degreasing treatment.

  A polyamide-imide resin is selected as a thermosetting synthetic resin, 100 parts by weight of a polyamide-imide resin (“HPC-5000-30 (trade name)” manufactured by Hitachi Chemical Co., Ltd.) and a polytetrafluoroethylene resin (PTFE: PTFE) as a lubricant additive. 10 parts by weight of “Lublon L-5 (trade name)” manufactured by Daikin Industries, Ltd. is uniformly dispersed in a mixed solvent of N-methyl-pyrrolidone, toluene and xylene, and a coating material (coating material) having a solid content concentration of 30% by weight ) Was produced.

  This coating material is sprayed on the surface of the back metal 2 made of oxygen-free copper, tough pitch copper, brass, phosphor bronze, aluminum and aluminum-magnesium alloy, which have been subjected to the shot blasting and degreasing treatment, and the temperature is 10 ° C. After drying for 30 minutes, the temperature is maintained at 160 ° C. for 30 minutes, and further heat-baked at 270 ° C. for 30 minutes, and then naturally cooled to form a lubricating coating layer 3 having a film thickness of 30 μm. Was a multilayer material 4 (see FIG. 2).

  The multilayer material 4 produced in this way was wound into a cylindrical shape by bending with the lubricating coating layer 3 inside, and a substantially cylindrical bearing bush 6 having a gap δ between the butted end surfaces 5 and 5 was produced (FIG. 3).

  Next, upsetting or sizing is performed on the substantially cylindrical bearing bush 6. In upset processing, the following two processing methods can be employed.

First Upset Processing Method As shown in FIG. 4, a mold body 13 having a large-diameter circular hole 12 defined by a large-diameter cylindrical inner wall surface 11 and the large-diameter circular hole 12 are adjacent to each other in the axial direction. A small diameter circular hole 16 having a diameter 15 smaller than the diameter 14 of the large diameter circular hole 12 and substantially equal to the inner diameter d (see FIG. 5) of the final cylindrical bearing bush 1. And between the large-diameter cylindrical inner wall surface 11 and the small-diameter cylindrical inner wall surface 18 that defines the small-diameter circular hole 16 in the radial direction. A mold 10 is prepared in which an annular surface 19 extending inward and terminating at a small-diameter cylindrical inner wall surface 18 is interposed.

  As shown in FIG. 4, a small-diameter cylindrical outer surface 22 having a diameter 21 that defines the inner diameter d of the final cylindrical bearing bush 1 is disposed adjacent to the small-diameter cylindrical outer surface 22 in the axial direction and adjacent to the upper side. A large-diameter cylindrical outer surface 24 having a diameter 23 larger than the diameter of the small-diameter cylindrical outer surface 22 and substantially equal to the diameter 14 of the large-diameter circular hole 12. A cored bar 20 is prepared between the cylindrical outer surface 24 and an annular surface 25 extending radially outward from the small-diameter cylindrical outer surface 22 and terminating at the large-diameter cylindrical outer surface 24.

  In the prepared metal mold 10 and the metal core 20, the substantially cylindrical bearing bush 6 is fitted on the small-diameter cylindrical outer surface 22 of the metal core 20, and then the metal core 20 is positioned with respect to the metal mold 10. Further, a load in the A direction is applied to the core metal 20 to move the core metal 20 toward the mold base 17 of the mold 10.

  Further, a part of the small-diameter cylindrical outer surface 22 of the core metal 20 is disposed in the small-diameter circular hole 16 of the mold 10, and the large-diameter cylindrical outer surface 24 of the core metal 20 is disposed in the large-diameter circular hole 12 of the mold 10. The substantially cylindrical bearing bush 6 is upset by the remainder of the small-diameter cylindrical outer surface 22 and the annular surfaces 19 and 25 of the mold 10 and the cored bar 20 (see FIG. 5).

  In this upset processing, the volume of the annular space S formed by the remaining portions of the large-diameter cylindrical inner wall surface 11 and the small-diameter cylindrical outer surface 22 and the annular surfaces 19 and 25 is close to the volume of the final cylindrical bearing bush 1. This is carried out by reducing the volume of the annular space S. By reducing the volume of the annular space S, an axial compressive force is applied to the substantially cylindrical bearing bush 6 to reduce the axial length of the substantially cylindrical bearing bush 6. The cylindrical bearing bush 1 in which the substantially cylindrical bearing bush 6 is plastically deformed in the radial direction on the basis of the reduction in the axial length and pressed against the large-diameter cylindrical inner wall surface 11 so that the butted end surfaces 5 and 5 are in close contact with each other. And The cylindrical bearing bush 1 is taken out from the mold 10.

Second Upset Processing Method As shown in FIG. 6, a mold body 33 having a circular hole 32 defined by a cylindrical inner wall surface 31 having a diameter that defines the final outer diameter of the substantially cylindrical bearing bush 6. And a metal receiver 38 having a recess 36 on one end 35 side and an annular end surface 37 surrounding the opening end surface of the recess 36 and a cylindrical outer surface 34 fitted to the cylindrical inner wall surface 31 of the mold body 33. 1 is prepared.

  As shown in FIG. 6, a small-diameter cylindrical outer surface 41 having a diameter that defines the final inner diameter of the substantially cylindrical bearing bush 6 and fitted in the recess 36 of the receiver 38, and a shaft on the small-diameter cylindrical outer surface 41. And a large-diameter cylindrical outer surface 42 having a diameter larger than that of the small-diameter cylindrical outer surface 41 and being arranged between the small-diameter cylindrical outer surface 41 and the large-diameter cylindrical outer surface 42. Prepares a cored bar 40 that includes an annular surface 43 that extends radially outward from the small-diameter cylindrical outer surface 41 and terminates at the large-diameter cylindrical outer surface 42.

  In the prepared metal mold 30 and the metal core 40, the substantially cylindrical bearing bush 6 is fitted to the small-diameter cylindrical outer surface 41 of the metal core 40, and then the metal receiver 38 is attached to the circular hole 32 of the metal mold body 33. A part of the small-diameter cylindrical outer surface 41 of the cored bar 40 that is disposed in the circular hole 32 from the one open end of the metal core 40 and is fitted with the substantially cylindrical bearing bush 6 on the small-diameter cylindrical outer surface 41 is the circular hole of the mold body 33. The other end of 32 is disposed in the recess 36 of the metal receiver 38, and a predetermined pressure is applied to each of the metal receiver 38 and the core metal 40 so that the remaining portion of the small-diameter cylindrical outer surface 41 and the annular end surface of the metal receiver 38 are provided. The substantially cylindrical bearing bush 6 is upset by 37 and the annular surface 43 of the core metal 40.

  In this upset process, the cylindrical inner wall surface 31 of the mold body 33, the remaining portion of the small-diameter cylindrical outer surface 41 of the core metal 40, the annular end surface 37 of the mold body 33, and the annular surface 43 of the core metal 40 are formed. The volume of the annular space S is reduced by applying a compressive force to the receiving metal 38 and the cored bar 40 until they are close to the volume of the final cylindrical bearing bush 1. While reducing the axial length of the substantially cylindrical bearing bush 6, the substantially cylindrical bearing bush 6 is plastically deformed in the radial direction on the basis of the reduction in the axial length, so that the cylindrical inner wall surface of the mold body 33 is The cylindrical bearing bush 1 is brought into pressure contact with the butt end face 5 and 5 and the butted end faces 5 and 5 are in close contact with each other. The cylindrical bearing bush 1 is taken out from the mold 30 and the cored bar 40.

  In the sizing process, the following two processing methods can be adopted.

First Sizing Method As shown in FIG. 7, the outer diameter of the final cylindrical bearing bush 1 is smaller than the outer diameter Dx of the substantially cylindrical bearing bush 6 and is the final outer diameter of the substantially cylindrical bearing bush 6. A mold 50 having a circular hole 53 defined by a cylindrical inner wall surface 52 having a diameter 51 that is substantially equal to the diameter 51 is prepared.

  As shown in FIG. 7, a small-diameter cylindrical outer surface 62 having a diameter 61 that defines the inner diameter d of the final cylindrical bearing bush 1, which is the final inner diameter of the cylindrical bearing bush 6, and an axial direction on the small-diameter cylindrical outer surface 62. And a large-diameter cylindrical outer surface 64 having a diameter 63 larger than the diameter of the small-diameter cylindrical outer surface 62 and substantially equal to the diameter 51 of the circular hole 53. A punch 60 is interposed between the cylindrical outer surface 62 and the large-diameter cylindrical outer surface 64, and has an annular surface 65 extending radially outward from the small-diameter cylindrical outer surface 62 and terminating at the large-diameter cylindrical outer surface 64. Prepare.

  In the prepared mold 50 and punch 60, the substantially cylindrical bearing bush 6 is press-fitted and fitted to one opening 54 side of the circular hole 53 of the mold 50 (see FIG. 7). Positioning with respect to the mold 50, and applying a load in the A direction to the punch 60, while holding the substantially cylindrical bearing bush 6 between the cylindrical inner wall surface 52 of the mold 50 and the small-diameter cylindrical outer surface 62 of the punch 60. The annular surface 65 of the punch 60 is pressed in the A direction to move in the circular hole 53 and is positioned in the circular hole 53 of the mold 50 (see FIG. 8).

  Next, the punch 60 is extracted from the circular hole 53 of the mold 50, the next substantially cylindrical bearing bush 6 is press-fitted into the one opening 54 side of the circular hole 53 of the mold 50, and the punch 60 is again fitted. Positioning with respect to the mold 50, and applying a load in the A direction to the punch 60, while holding the substantially cylindrical bearing bush 6 between the cylindrical inner wall surface 52 of the mold 50 and the small-diameter cylindrical outer surface 62 of the punch 60. Cylindrical bearing bush that has been subjected to sizing from the other opening 55 side of the circular hole 53 of the mold 50 by repeatedly pressing the annular surface 65 of the punch 60 to move in the A direction in the circular hole 53. 1 is discharged (see FIGS. 9 to 11).

  In this sizing method, the substantially cylindrical bearing bush 6 is plastically deformed in the radial direction to form the cylindrical bearing bush 1 in which the butted end surfaces 5 and 5 are in close contact with each other.

Second Sizing Method As shown in FIG. 12, a large-diameter circular hole 72 that is smaller than the outer diameter Dx of the substantially cylindrical bearing bush 6 and is defined by a large-diameter cylindrical inner wall surface 71, and the large-diameter circular hole 72 and a tapered hole 74 defined by a truncated conical surface 73 that gradually decreases in diameter in the axial direction as it leaves the large-diameter circular hole 72, and has a smaller diameter than the large-diameter circular hole 72. A mold 70 having a small-diameter circular hole 77 defined by a cylindrical inner wall surface 76 having a diameter 75 that defines the outer diameter of the final cylindrical bearing bush 1, which is the final outer diameter of the substantially cylindrical bearing bush 6. prepare. Here, the inclination angle α of the truncated conical surface 73 with respect to the large-diameter cylindrical inner wall surface 71 of the mold 70 is 0.5 ° to 5 °.

  As shown in FIG. 12, a small-diameter cylindrical outer surface 82 having a diameter 81 that defines the inner diameter d of the final cylindrical bearing bush 1 that is the final inner diameter of the cylindrical bearing bush 6, and an axial direction on the small-diameter cylindrical outer surface 82. A large-diameter cylindrical outer surface 84 disposed adjacent to the upper side and having a diameter 83 that is larger than the diameter of the small-diameter cylindrical outer surface 82 and substantially equal to the diameter of the large-diameter circular hole 72; A punch formed between the small-diameter cylindrical outer surface 82 and the large-diameter cylindrical outer surface 84 is an annular surface 85 extending radially outward from the small-diameter cylindrical outer surface 82 and terminating at the large-diameter cylindrical outer surface 84. Prepare 80.

  In the prepared mold 70 and punch 80, the substantially cylindrical bearing bush 6 is press-fitted into one opening 78 side of the large-diameter circular hole 72 of the mold 70, and then the punch 80 is inserted into the mold 70. The cylindrical bearing bush 6 is sandwiched between the large-diameter cylindrical inner wall surface 71 of the mold 70 and the small-diameter cylindrical outer surface 82 of the punch 80 while applying a load in the A direction to the punch 80. The annular surface 85 of the punch 80 is pressed in the A direction to move in the large-diameter circular hole 72 of the mold 70 and is positioned in the large-diameter circular hole 72 of the mold 70.

  Next, the punch 80 is extracted from the large-diameter circular hole 72 of the mold 70, and the next substantially cylindrical bearing bush 6 is press-fitted and fitted into one opening 78 side of the large-diameter circular hole 72 of the mold 70. Then, the punch 80 is positioned with respect to the mold 70, and further, a load in the A direction is applied to the punch 80 so that the substantially cylindrical bearing bush 6 is connected to the large-diameter cylindrical inner wall surface 71 of the mold 70 and the small-diameter cylindrical outer surface of the punch 80. The operation of pressing in the direction A with the annular surface 85 of the punch 80 and moving the inside of the large diameter circular hole 72 is repeated. By this repeated operation, the substantially cylindrical bearing bush 6 first press-fitted to the one opening 78 side of the mold 70 moves from the large diameter circular hole 72 to the small diameter circular hole 77 via the tapered hole 74, Finally, the cylindrical bearing bush 1 is discharged from the other opening 79 side of the mold 70 as a sizing-processed cylindrical bearing bush 1 (see FIG. 13).

  In this sizing method, the substantially cylindrical bearing bush 6 is squeezed in the taper hole 74 of the mold 70 and plastically deformed radially inward to form the cylindrical bearing bush 1 in which the butted end surfaces 5 and 5 are in close contact with each other. Further, in this sizing method, the substantially cylindrical bearing bush 6 is squeezed when moving through the taper hole 74 of the mold 70, so that the final thickness of the cylindrical bearing bush 1 is approximately the thickness of the cylindrical bearing bush 6. It becomes thinner than the thickness.

  Experimental results of measuring the roundness of the inner diameter d of the cylindrical bearing bush 1 after using the above-described substantially cylindrical bearing bush 6 and subjecting the substantially cylindrical bearing bush 6 to the first upset process and the second sizing process. Will be described.

  As a test body, a multilayer material (B) having a backing metal 2 made of oxygen-free copper, a multilayer material (C) having a backing metal 2 made of tough pitch copper, and a multilayer material having a backing metal 2 made of brass (D ), A multilayer material (E) having a backing metal 2 made of phosphor bronze, a multilayer material (F) having a backing metal 2 made of aluminum, and a multilayer material having a backing metal 2 made of an aluminum-magnesium alloy (G) ), And a cold rolled steel plate (SPCC) having a thickness of 0.80 mm, which is a conventional technology, is used as a back metal 2, and a multi-layer material in which a lubricating coating layer 3 having a thickness of 30 μm is formed on the back metal 2 in the same manner as described above ( Each of H) was prepared by preparing two substantially cylindrical bearing bushes 6 each of which was bent with the lubricating coating layer 3 inside and wound into a cylindrical shape.

First upset processing Specimen B-1: Thickness 0.83mm
Inner diameter 10.32 mm, outer diameter 12.02 mm, length 10.2 mm, butted
Gap between laying end faces (δ) 0.5mm
Specimen B-2: Thickness 0.83mm
Inner diameter 10.36 mm, outer diameter 12.04 mm, length 10.3 mm, butted
Gap between laying end faces (δ) 0.4mm
Specimen C-1: thickness 0.83 mm
Inner diameter 10.30mm, outer diameter 12.02mm, length 10.3mm, butt
Gap between laying end faces (δ) 0.5mm
Specimen C-2: thickness 0.83 mm
Inner diameter 10.35 mm, outer diameter 12.02 mm, length 10.3 mm, butted
Gap between laying end faces (δ) 0.5mm
Specimen D-1: thickness 0.83 mm
Inner diameter 10.40mm, outer diameter 12.04mm, length 10.2mm, butting
Gap between laying end faces (δ) 0.6mm
Specimen D-2: thickness 0.83 mm
Inner diameter 10.40mm, outer diameter 12.08mm, length 10.3mm, butting
Gap between laying end faces (δ) 0.5mm
Specimen E-1: 0.83 mm thick
Inner diameter 10.35 mm, outer diameter 12.06 mm, length 10.2 mm, butting
Gap between laying end faces (δ) 0.5mm
Specimen E-2: thickness 0.83 mm
Inner diameter 10.40mm, outer diameter 12.10mm, length 10.3mm, butting
Gap between laying end faces (δ) 0.6mm
Specimen F-1: thickness 0.83 mm
Inner diameter 10.35 mm, outer diameter 12.02 mm, length 10.3 mm, butted
Gap between laying end faces (δ) 0.4mm
Specimen F-2: thickness 0.83 mm
Inner diameter 10.32 mm, outer diameter 12.00 mm, length 10.4 mm, butted
Gap between laying end faces (δ) 0.4mm
Specimen G-1: thickness 0.83 mm
Inner diameter 10.34 mm, outer diameter 12.02 mm, length 10.4 mm, butted
Gap between laying end faces (δ) 0.4mm
Specimen G-2: thickness 0.83 mm
Inner diameter 10.32 mm, outer diameter 12.00 mm, length 10.4 mm, butted
Gap between laying end faces (δ) 0.4mm
Specimen H-1: 0.83 mm thick
Inner diameter 10.35 mm, outer diameter 12.06 mm, length 10.3 mm, butted
Gap between laying end faces (δ) 0.6mm
Specimen H-2: thickness 0.83 mm
Inner diameter 10.40mm, outer diameter 12.08mm, length 10.2mm, butting
Gap between laying end faces (δ) 0.7mm

<Specifications of mold 10 and core 20>
Diameter of the large-diameter circular hole 12 of the mold 10: 12.00 mm
The outer diameter of the small cylindrical outer surface 22 of the cored bar 20 is 10.20 mm.

<Test method>
Each test specimen is fitted to the small-diameter cylindrical outer surface 22 of the core metal 20, the core metal 20 is positioned with respect to the mold 10, and a load of 1.0 KN / mm ² is applied to the core metal 20 to upset the test specimen. To give a cylindrical bearing bush 1,
(1) Roundness of inner peripheral surface at a position of 3 mm from one end of each cylindrical bearing bush 1 in a state of being held in the mold 10 (2) The cylindrical bearing bush 1 was taken out from the mold 10 The roundness of the inner peripheral surface at a position 3 mm from one end of each cylindrical bearing bush 1 in the state was measured.

  The test results are shown in Table 1.

As a second sizing test specimen, a back metal 2 made of oxygen-free copper, tough pitch copper, aluminum-magnesium alloy having a thickness of 0.8 mm, and a cold-rolled steel sheet, which is a conventional technology, is prepared. After the surface treatment similar to that described above was performed on the surfaces of these backing plates, a multilayer having a backing plate 2 made of oxygen-free copper, in which a lubricating coating layer 3 having a thickness of 20 μm was formed by heating and baking the same coating material as described above. A composite material (B), a multilayer material (C) having a backing metal 2 made of tough pitch copper, a multilayer material (G) having a backing metal 2 made of an aluminum-magnesium alloy, and a cold rolled steel sheet as a backing metal 2. A plurality of substantially cylindrical bearing bushes 6 were prepared by preparing a layer material (H) and winding the multilayered material into a cylindrical shape by bending the lubricating coating layer 3 inside.

Specimen B: Thickness 0.82mm
Inner diameter 10.3 ± 0.1 mm, outer diameter 12.0 ± 0.1 mm, length 10.0 ± 0. 1 mm, gap between butt end faces (δ) 0.4 mm Multiple Specimen C: Thickness 0.82 mm
Inner diameter 10.3 ± 0.1 mm, outer diameter 12.0 ± 0.1 mm, length 10.0 ± 0. 1 mm, gap between butt end faces (δ) 0.4 mm Multiple specimen G: thickness 0.82 mm
Inner diameter 10.3 ± 0.1 mm, outer diameter 12.0 ± 0.1 mm, length 10.0 ± 0. 1 mm, gap between butt end faces (δ) 0.4 mm Multiple specimen H: thickness 0.82 mm
Inner diameter 10.4 ± 0.1 mm, outer diameter 12.1 ± 0.1 mm, length 10.0 ± 0. 1mm, gap between butt end faces (δ) 0.6mm

The specifications of the mold 70 and the punch 80 are as follows.
<Specifications of mold 70>
Diameter of large-diameter circular hole 72: 12.0 mm, inclination angle α: 1.4 °, length of tapered hole 74: 10 mm, diameter of small-diameter circular hole 77: 11.5 mm
<Specifications of punch 80>
Diameter of small-diameter cylindrical outer surface 82: 10.0 mm, diameter of large-diameter cylindrical outer surface 84: 11.9 mm

<Test method>
The substantially cylindrical bearing bush 6 is press-fitted into one opening 78 side of the large-diameter circular hole 72 of the mold 70, and then the punch 80 is positioned with respect to the mold 70, and the load in the A direction is applied to the punch 80. In addition, the substantially cylindrical bearing bush 6 is pressed between the large diameter cylindrical inner wall surface 71 of the mold 70 and the small diameter cylindrical outer surface 82 of the punch 80 in the A direction by the annular surface 85 of the punch 80. The inside of the large-diameter circular hole 72 of the mold 70 is moved and positioned within the large-diameter circular hole 72 of the mold 70. Next, the punch 80 is extracted from the large-diameter circular hole 72 of the mold 70, and the next substantially cylindrical bearing bush 6 is press-fitted and fitted into one opening 78 side of the large-diameter circular hole 72 of the mold 70. The punch 80 is positioned with respect to the mold 70, and a load in the A direction is applied to the punch 80, so that the substantially cylindrical bearing bush 6 is connected to the large diameter cylindrical inner wall surface 71 of the mold 70 and the small diameter cylindrical outer surface 82 of the punch 80. The cylindrical bearing bush 6 is moved from the large-diameter circular hole 72 to the tapered hole 74 by repeating the operation of pressing the annular surface 85 of the punch 80 and moving the inside of the large-diameter circular hole 72 in the A direction. Then, the cylindrical bearing bush 1 is discharged from the other opening 79 side of the large diameter circular hole 72 of the mold 70 as a cylindrical bearing bush 1. The roundness of the inner peripheral surface at a position of 3 mm from one end face of each cylindrical bearing bush 1 was measured for the five cylindrical bearing bushes 1 subjected to sizing in this way.

  The test results are shown in Table 2.

  From the test results of Table 1 and Table 2, the test bodies B, C, D, E, F, and G are cylindrical bearing bushes 1 obtained by the manufacturing method of the present invention, and the conventional cylindrical bearing bush of the test body H. It is clear that the roundness of the inner peripheral surface is clearly increased compared with. In the cylindrical bearing bush 1 of the test bodies B, C, D, E, F, and G, it was confirmed that the butted end surfaces 5 and 5 after the upset processing and after the sizing processing are in close contact with each other. In the cylindrical bearing bush of the test body H, it was confirmed that a gap due to the spring back was generated between the butt end faces after any processing.

  As described above, according to the present invention, the butted end faces are brought into close contact with each other, and the cylindrical bearing bush having an extremely high roundness without subjecting the inner peripheral surface to machining such as cutting and grinding, and a method for manufacturing the same Can be provided.

It is a perspective view of the cylindrical bearing bush obtained by the manufacturing method of this invention. It is sectional drawing of the multilayer material for forming the cylindrical bearing bush shown in FIG. It is a perspective view of the substantially cylindrical bearing bush in the manufacturing method of this invention. It is sectional drawing of the upset apparatus which consists of a metal mold | die and a core metal suitable for the method of this invention. It is explanatory drawing of the last process of the method of this invention. It is sectional drawing of the upset apparatus which consists of another metal mold | die and a core metal suitable for the method of this invention. It is sectional drawing of the sizing processing apparatus which consists of a metal mold | die and a punch suitable for the manufacturing method of this invention. It is sectional drawing which shows the manufacturing process of the cylindrical bearing bush in the manufacturing method of this invention. It is sectional drawing which shows the manufacturing process of the cylindrical bearing bush in the manufacturing method of this invention. It is sectional drawing which shows the manufacturing process of the cylindrical bearing bush in the manufacturing method of this invention. It is sectional drawing which shows the manufacturing process of the cylindrical bearing bush in the manufacturing method of this invention. It is sectional drawing of the sizing processing apparatus which consists of another metal mold | die and punch suitable for use in the manufacturing method of this invention. It is sectional drawing which shows the manufacturing process of the cylindrical bearing bush in the manufacturing method of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cylindrical bearing bush 2 Back metal 3 Lubrication coating layer 4 Multi-layer material 5 Butt end surface 6 Substantially cylindrical bearing bush 10, 30 Mold 13, 33 Mold main body 17 Mold base
20, 40 Core 50, 70 Die 60, 80 Punch

Claims (12)

  It comprises a plate-like backing metal made of a non-ferrous metal and a sliding layer made of a synthetic resin composition integrally formed on the surface of the backing metal, and is wound in a cylindrical shape with the sliding layer inside. The cylindrical bearing bush is characterized in that the abutting end surfaces are in close contact with each other and the roundness of the inner peripheral surface is 3 to 15 μm.   2. The cylindrical bearing bush according to claim 1, wherein the plate-like backing metal made of a non-ferrous metal is selected from any one of copper, a copper alloy, aluminum, and an aluminum alloy.   The synthetic resin composition is mainly composed of a thermosetting synthetic resin selected from an epoxy resin, a polyimide resin and a polyamide-imide resin, and includes graphite, molybdenum disulfide, ethylene tetrafluoride resin, boron nitride and melamine cyanurate. The cylindrical bearing bush according to claim 1 or 2, comprising at least one selected lubricating additive in a proportion of 2 to 60 vol%. A multilayer material comprising a plate-like backing metal made of a non-ferrous metal and a sliding layer made of a synthetic resin composition integrally formed on the surface of the backing metal is wound into a cylindrical shape with the sliding layer inside. A step of forming a substantially cylindrical bearing bush having a gap at the butt end surface;
A large-diameter circular hole defined by a large-diameter cylindrical inner wall surface and a small-diameter circular hole that is disposed adjacent to the large-diameter circular hole in the axial direction and has a smaller diameter than the large-diameter circular hole And between the large-diameter cylindrical inner wall surface and the small-diameter cylindrical inner wall surface defining the small-diameter circular hole, extending radially inward from the large-diameter cylindrical inner wall surface and terminating at the small-diameter cylindrical inner wall surface A step of preparing a mold having an annular surface to be interposed;
A small cylindrical outer surface having a diameter that defines the final inner diameter of the substantially cylindrical bearing bush and an axially adjacent to the small diameter cylindrical outer surface and a large diameter larger than the small diameter cylindrical outer surface A cylindrical outer surface, and a ring between the small-diameter cylindrical outer surface and the large-diameter cylindrical outer surface that extends radially outward from the small-diameter cylindrical outer surface and terminates at the large-diameter cylindrical outer surface A step of preparing a mandrel with an intervening surface;
Fitting a substantially cylindrical bearing bush on the small-diameter cylindrical outer surface of the core;
A part of the small-diameter cylindrical outer surface of the metal core having a substantially cylindrical bearing bush fitted to the small-diameter cylindrical outer surface is used as the small-diameter small-diameter hole of the metal mold, and the large-diameter cylindrical outer surface of the metal core is used as the large-diameter circle of the metal mold. Each of which is arranged in the hole, and a predetermined pressure is applied to the core metal to subject the remaining portion of the small-diameter cylindrical outer surface and the annular surface of the mold and the core metal to upset the substantially cylindrical bearing bush;
After the upset process, the cylindrical bearing bush whose butted end faces are in close contact with each other is taken out from the mold, and a cylindrical bearing bush formed with a roundness of 3 to 15 μm on the inner peripheral surface is obtained;
A method of manufacturing a cylindrical bearing bush comprising:   The volume of the annular space formed by the large-diameter cylindrical inner wall surface and the remainder of the small-diameter cylindrical outer surface of the core metal and the annular surfaces of the mold and the core metal is approximately the volume of the cylindrical bearing bush. The method for manufacturing a cylindrical bearing bush according to claim 4, wherein the upset process is performed while reducing the upset process. A multilayer material comprising a plate-like backing metal made of a non-ferrous metal and a sliding layer made of a synthetic resin composition integrally formed on the surface of the backing metal is wound into a cylindrical shape with the sliding layer inside. A step of forming a substantially cylindrical bearing bush having a gap at the butt end surface;
A die body having a circular hole defined by a cylindrical inner wall surface having a diameter defining the final outer diameter of the substantially cylindrical bearing bush, and having a recess on one end side and surrounding an opening surface of the recess Preparing a mold having an annular end surface and a receiver having a cylindrical outer surface fitted to a cylindrical inner wall surface of the mold body;
A small cylindrical outer surface having a diameter defining the final inner diameter of the substantially cylindrical bearing bush, and being arranged adjacent to the small cylindrical outer surface in the axial direction and being inserted in the recess of the receiver. A large-diameter cylindrical outer surface having a diameter larger than that of the cylindrical outer surface, and extends radially outward from the small-diameter cylindrical outer surface between the small-diameter cylindrical outer surface and the large-diameter cylindrical outer surface. Preparing a cored bar having an annular surface that terminates at a large cylindrical outer surface;
Fitting a substantially cylindrical bearing bush on the small-diameter cylindrical outer surface of the core;
A part of the small-diameter cylindrical outer surface of the core metal in which a substantially cylindrical bearing bush is fitted to the small-diameter cylindrical outer surface is inserted into the circular hole from one open end of the circular hole of the mold main body. The other end of the circular hole is arranged in the recess of the receiving metal, and a predetermined pressure is applied to the receiving metal and the cored bar so that the remaining portion of the outer surface of the small-diameter cylindrical shape, the annular end surface of the receiving metal and the annular shape of the cored bar A process of upsetting the substantially cylindrical bearing bush depending on the surface;
After the upset process, the cylindrical bearing bush whose butted end faces are in close contact with each other is taken out from the mold, and a cylindrical bearing bush formed with a roundness of 3 to 15 μm on the inner peripheral surface is obtained;
A method of manufacturing a cylindrical bearing bush comprising:   The volume of the annular space formed by the cylindrical inner wall surface, the remainder of the small-diameter cylindrical outer surface of the cored bar, the annular end surface of the receiving bar and the annular surface of the cored bar until the volume becomes approximately the volume of the cylindrical bearing bush. The method for manufacturing a cylindrical bearing bush according to claim 6, wherein the upset process is performed by decreasing the number. A multilayer material comprising a plate-like backing metal made of a non-ferrous metal and a sliding layer made of a synthetic resin composition integrally formed on the surface of the backing metal is wound into a cylindrical shape with the sliding layer inside. A step of forming a substantially cylindrical bearing bush having a gap at the butt end surface;
Preparing a mold having a circular hole defined by a cylindrical inner wall surface having a diameter defining a final outer diameter of the substantially cylindrical bearing bush;
A small cylindrical outer surface having a diameter that defines the final inner diameter of the substantially cylindrical bearing bush and an axially adjacent to the small cylindrical outer surface and a large diameter larger than the diameter of the small cylindrical outer surface A cylindrical outer surface, and an annular surface between the small-diameter cylindrical outer surface and the large-diameter cylindrical outer surface that extends radially outward from the small-diameter cylindrical outer surface and terminates at the large-diameter cylindrical outer surface. A step of preparing a punch intervening,
The substantially cylindrical bearing bush is press-fitted into a circular hole of the mold, and the substantially cylindrical bearing bush is sandwiched between the cylindrical inner wall surface of the mold and the small-diameter cylindrical outer surface of the punch, and the annular surface of the punch A step of applying sizing to move in the circular hole by pressing,
After the sizing process, a cylindrical bearing bush whose butted end faces are in close contact with each other is taken out of the mold, and a cylindrical bearing bush formed with a roundness of 3 to 15 μm on the inner peripheral surface is obtained;
A method of manufacturing a cylindrical bearing bush comprising: A multilayer material comprising a plate-like backing metal made of a non-ferrous metal and a sliding layer made of a synthetic resin composition integrally formed on the surface of the backing metal is wound into a cylindrical shape with the sliding layer inside. A step of forming a substantially cylindrical bearing bush having a gap at the butt end surface;
A large-diameter circular hole defined by a large-diameter cylindrical inner wall surface and a truncated conical surface that is continuous with the large-diameter circular hole and that gradually decreases in diameter in the axial direction. A die having a tapered hole and a small-diameter circular hole defined by a cylindrical inner wall surface having a diameter smaller than the large-diameter circular hole and having a diameter that defines the final outer diameter of the substantially cylindrical bearing bush And a process of
A small cylindrical outer surface having a diameter that defines the final inner diameter of the substantially cylindrical bearing bush and an axially adjacent to the small cylindrical outer surface and a large diameter larger than the diameter of the small cylindrical outer surface A cylindrical outer surface, and an annular surface between the small-diameter cylindrical outer surface and the large-diameter cylindrical outer surface that extends radially outward from the small-diameter cylindrical outer surface and terminates at the large-diameter cylindrical outer surface. A step of preparing a punch intervening,
The substantially cylindrical bearing bush is press-fitted into the large-diameter circular hole of the mold, and the punch is held while the substantially cylindrical bearing bush is sandwiched between the large-diameter cylindrical inner wall surface of the mold and the small-diameter cylindrical outer surface of the punch. A step of performing sizing by sequentially pressing the taper hole and the small-diameter circular hole of the mold by pressing with the annular surface;
After the sizing process, a cylindrical bearing bush whose butted end faces are in close contact with each other is taken out of the mold, and a cylindrical bearing bush formed with a roundness of 3 to 15 μm on the inner peripheral surface is obtained;
A method of manufacturing a cylindrical bearing bush comprising:   The method for manufacturing a cylindrical bearing bush according to claim 9, wherein an inclination angle of the truncated conical surface with respect to the large-diameter cylindrical inner wall surface of the mold is 0.5 to 5 °.   The method for manufacturing a cylindrical bearing bush according to any one of claims 4 to 10, wherein the plate-like backing metal made of a non-ferrous metal is selected from any one of copper, a copper alloy, aluminum, and an aluminum alloy.   The synthetic resin composition is mainly composed of a thermosetting synthetic resin selected from an epoxy resin, a polyimide resin and a polyamide-imide resin, and includes graphite, molybdenum disulfide, ethylene tetrafluoride resin, boron nitride and melamine cyanurate. The method for manufacturing a cylindrical bearing bush according to any one of claims 4 to 11, comprising at least one selected lubricating additive in a ratio of 2 to 60 vol%.

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